Cambridge Past Paper Questions
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Which statements about the apoplast and symplast pathways are correct? 1 In the apoplast pathway, water molecules move through free spaces in the c...
The diagram shows the outline of three xerophytic leaves of the same type in three different conditions, P, R and S. [Figure 29.1] Which descriptio...
The photomicrograph shows a transverse section of the leaf of a species of grass. [Figure 30.1] The grass is specially adapted to grow in a dry hab...
Which statement supports the theory of active loading of sucrose into companion cells?
Which properties of water are essential for its role in the transport of blood in mammals?
The diagram shows some of the events that happen between the plasma and the red blood cells in the circulatory system. [Figure 33.1] What do the nu...
The diagrams show the valves in the heart when viewed in cross-section from above at different stages in the cardiac cycle. [Figure 34.1] (diagram ...
Where are squamous epithelial cells found in the human gas exchange system?
Which statement about gas exchange between air in the alveoli and blood in the pulmonary capillaries is correct?
The average thicknesses for some structures in the human respiratory system are shown. [Figure 37.1] A molecule of oxygen is in the alveolar air sp...
The statements refer to the disease tuberculosis (TB). 1 The pathogen is not accessible to the immune system. 2 The bacterial pathogen reproduces s...
The average sizes of some pathogens are shown. [Figure 39.1] One type of air filter has been shown to be effective at preventing any pathogens of 1...
A successful vaccination programme provides a level of immunity where the majority of a population is protected. There are several factors that can...
Fig. 1.1 is a transmission electron micrograph of a cell from the stem of sago pondweed, Stuckenia pectinata.
Glycogen and cellulose are polymers. Fig. 2.1 shows small, representative regions of a glycogen molecule and a cellulose molecule.
Fig. 3.1 shows some fruits (grapes) of the grapevine, Vitis vinifera. Sucrose is transported in the phloem of the grapevine to the fruits. In the f...
The gene for the enzyme catalase is on chromosome 11 in humans.
Fig. 5.1 is a longitudinal section of a capillary in muscle tissue as viewed with a transmission electron microscope.
Fig. 6.1 is a diagram showing the passage of water through the tissues of a flowering plant from the soil to the atmosphere. The arrows show the di...
The sinoatrial node (SAN) and the atrioventricular node (AVN) have an important role in the control of the cardiac cycle. The timing of atrial and ...
Fig. 2.1 is a photomicrograph of a longitudinal section (LS) through a root tip. Two different regions are visible: • the root apical meristem • th...
Cells of the immune system respond to the presence of non-self antigens.
Trypanosoma brucei is a unicellular organism that causes the infectious disease known as sleeping sickness. Insects known as tsetse flies pass on t...
Nucleotide and nucleoside analogues are therapeutic drugs that have a similar structure to nucleotides or nucleosides of RNA and DNA. A nucleoside...
The Weibel Lung model was developed after an extensive study of the gas exchange system. The model includes detailed measurements of airway diamete...
The cells in a tissue are often at different stages of the cell cycle.
The number of cases of tuberculosis (TB) is affected by many biological, social and economic factors.
Blood contains white blood cells and red blood cells.
Food crops such as barley and wheat contain gluten. Gluten contains two proteins, glutenin and gliadin.
Phloem and xylem are specialised tissues involved in the transport of water, ions and assimilates in plants.
Polysaccharides, such as glycogen, are composed of thousands of monomers. Oligosaccharides are carbohydrates that contain three to ten monomers in ...
Yeast cells contain the enzyme catalase which catalyses the breakdown of hydrogen peroxide, releasing oxygen. You will investigate the effect of pH...
Grapes are fruit that contain high concentrations of soluble sugars such as sucrose, fructose and glucose. The proportions of these sugars change a...
K1 is a slide of a stained transverse section through a plant root.
When milk is dropped into a test-tube containing copper sulfate solution, the drop of milk sinks to the bottom of the test-tube. The speed at which...
L1 is a slide of a stained transverse section through a plant root.
Fig. 1.1 shows a transmission electron micrograph of part of a chloroplast. [Figure 1.1]
The natural ecosystem on Hawadax Island in Alaska was disrupted in the 1780s when brown rats, Rattus norvegicus, swam to the island from a sinking ...
Oryza is a genus of grass plants that includes the rice, Oryza sativa, a food crop.
Recombinant human proteins can be used to treat disease.
The kidney is an important organ of homeostasis. One role of the kidney is osmoregulation. (a) Fig. 5.1 is a photomicrograph of part of a kidney ne...
Domestic rabbits vary in the length and colour of their fur. Fig. 6.1 shows a domestic rabbit with short fur and a fur colour pattern called Himala...
Amino acids are the monomers that are used to produce proteins in organisms. Amino acids also have other, non-protein, roles in the body. Fig. 7.1 ...
Fig. 8.1 shows a cell from the testis of a locust at the late prophase I stage of meiosis. [Figure 8.1]
Many factors affect the rate of cellular respiration.
Sweet peas are garden plants that vary in height. • Tall sweet peas grow to 200 cm in height. • Dwarf sweet peas grow to 30 cm in height. • Tall sw...
(a) Glycolysis is a biochemical pathway that occurs in the cytoplasm of cells. In glycolysis, a molecule of glucose is metabolised to two molecule...
(a) In sexual reproduction, meiosis occurs to produce haploid gametes from a diploid cell.
(a) The sea blush, Plectritis congesta, is a flowering plant that grows on the west coast of North America. Individual sea blush plants produce fr...
Genetic technology uses many different enzymes and techniques. (a) Restriction endonucleases are used in genetic modification. These enzymes occur...